Reproductive health apps: the risks of sharing your most intimate data with the Femtech industry

The adoption of mobile apps for monitoring aspects of women's health, such as fertility, pregnancy, menstruation and menopause, is on the rise. These apps are part of the so-called Femtech industry, which was valued at $45.6 billion last year and is projected to continue growing to more than $100 billion by 2033.

This technology has a positive impact on the lives of many women, as it provides an affordable and accessible way of tracking menstrual cycles, contraception and family planning. However, the fact that these platforms handle vast amounts of highly sensitive data about women's health raises critical privacy concerns about the potential for unethical use by these companies, particularly given the lack of a specific legal framework for the industry.

Although the General Data Protection Regulation (GDPR) and Spain's Organic Law on the Protection of Personal Data and Guarantee of Digital Rights (LOPDGDD) should protect the privacy of users of Femtech apps, several studies have shown that a significant number of these apps do not comply with legal requirements. Moreover, the regulation "does not take into account the gender perspective or issues related to users' reproductive rights and privacy, so they are not legally protected when they use these apps", explained Luana Mathias Souto, a researcher in the GenTIC group at the UOC and lead author of the study Data Protection, Privacy and Reproductive Rights in Femtech: Evidence from Play Store User Reviews, published in Sexuality Research and Social Policy. The study was supported by a Marie Skłodowska-Curie (MSCA) postdoctoral fellowship under European Union funding.

The study is part of a broader UOC project called THELMA (Reproductive Health Under Algorithm Surveillance), which examines the impact of algorithmic surveillance by the Femtech industry on reproductive health. 

More than 90,000 reviews of Femtech apps

Mathias Souto, in collaboration with Jörg Müller, another researcher in the GenTIC group, part of the Interdisciplinary Research Centre on Social and Cultural Transformations (UOC-TRÀNSIC), analysed more than 90,000 user reviews of 20 Femtech apps posted on the Google Play Store in 2025.

The apps were selected based on their high number of downloads, relevance and visibility: Clue, Flo, Pregnancy+, Glow, Period Calendar, Oura, OvuView, Stardust, Ovia, WomanLog, Maya, Premom, Natural Cycles, Kindara, FEMM, My Calendar, ReadYourBody, Drip, Garmin and Zepp.

The analysis focused on areas such as medical issues, data security, commercial aspects, diversity and inclusion, interpersonal relationships and technological issues. The researchers used a structural topic modelling (STM) method, a statistical natural language processing technique that identifies latent topics in large volumes of text and links them to variables such as app ratings. They also conducted a qualitative analysis of critical issues related to data privacy and reproductive rights.

Unplanned pregnancies and unsafe medical recommendations

The research revealed negative experiences among users who had had unplanned and unintended pregnancies despite following the app's recommendations. Other women received medical recommendations that they considered unsafe, inaccurate or intrusive. "In some cases, the recommendations generated by the apps directly contradicted established medical consensus, including on sensitive issues such as care after a miscarriage. We also observed that users are now more distrustful of these apps, particularly at a time of legal changes around abortion in the United States and other countries, as data stored in the app could potentially be used as evidence in legal proceedings," explained Mathias Souto. 

The reality is that many of these apps are classified in app stores as health and wellness apps, which allows developers to avoid costly clinical validation processes and the stricter oversight that would apply if they were classified as medical apps. As a result, many lack clinical validation and do not comply with current regulations in this area. "Many apps used by consumers as a form of contraception have not been validated as medical devices. For example, most apps use a menstrual cycle range of 24-48 days, but this does not apply to all women. We therefore found many user reviews that described the impact of these inaccurate predictions, including unintended pregnancies," explained the researcher. 

The study shows that, although data privacy in relation to reproductive rights is a "minor" concern among users, they are critical of the lack of access to their data, a situation that some had experienced. Some users had reported losing access to health data collected over several years due to technical issues caused by software updates or a change of device, without the platforms providing an adequate solution. Similarly, some users were unable to download their information or delete their personal accounts, along with the data they had accumulated in the app over time.

Another challenge encountered in the Femtech industry, explained the researcher, is "the sale of intimate data that occurs in some apps. We have verified information on this, and users were not aware that their data was being exploited for commercial purposes."

A guide to protecting sensitive data in the Femtech context

As a result of this research and as a key part of the THELMA project, researchers from the UOC, together with international experts from academia, industry and non-profit organizations, have launched Who’s Watching: A guide to protect your intimate data in the Femtech context, an educational guide that provides key concepts and recommendations on the use of Femtech apps, with the aim of mitigating risks related to data privacy and protecting reproductive rights. The resource is available in Catalan, Spanish and English, and will soon be available in other languages.

In addition to empowering users in relation to the monitoring and protection of their intimate data, Mathias Souto considers it essential that women are involved in the development of the Femtech industry, from programming and clinical research through to app design and the funding of entrepreneurial projects. "Femtech needs to overcome structural gender inequalities to ensure that products better protect user rights. This presence could also help tackle gender biases and other stereotypes that are common in these apps," she added. 

This research contributes to Sustainable Development Goals (SDGs) 3, Good Health and Well-Being, and 5, Gender Equality, and is aligned with the UOC's research missionsPlanetary health and well-being and Ethical and human-centred technology. 

Reference article:

Souto, L. [Luana] & Müller, J. [Jörg]. (2026). Data protection, privacy and reproductive rights in Femtech: Evidence from Play Store user reviews. Sexuality Research and Social Policy. https://doi.org/10.1007/s13178-026-01404-8

The study was carried out within the framework of a Marie Skłodowska-Curie Actions (MSCA) postdoctoral fellowship, with funding from the European Union under grant agreement No. 101149321.

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